Pump governor



M.- E. ERsKlNE PUMPGOVERNOR Filed May 2l, 1934 n w .v f

INVETOR* f kwa... imm

Qua/em rm ATTORNEYS Patented Dec. 15, 1936 UNITED s'rmissl PUMP GOVERNOR Malcolm E. Erskine, Racine, Wis., assigner to Racine Tool and Machine Company, Racine, Wis., a corporationof Wisconsin Application May 21', 1934, serial No. 726,718

- 2 Claims.

The invention relates to pump governors and more particularly to a governor for controlling the output of a rotary vane' type hydraulic pump.

The object of the invention is to provide a with a rod I8 which extends through a bore I9 simple mechanism for automatically governing the eccentricity of the outerbarrel lof a vane type rotary hydraulic pump, so lthat the pressure of the uid furnished by the pump will be s ubstantially constant.

The invention further consists in the several features hereinafter set forth and more particularly defined by claims at the conclusion hereof.

The drawing shows a vertical sectional view of a rotary vane type pump and the governor mechanism therefor embodying the invention.

The pump herein shown is a vane type rotary pump and more particularly one having a fixed valve shaft, as for example, like the rotary pump of the U. S. patent to Percy O. Ott, No. 1,965,388, dated July 3, 1934. y

Briefly the pump includes a valve shaft 2 having an inlet port 3, a discharge port 4 and passages (not shown) in said shaft communicating with said ports and a rotor 5 cooperating with said shaft and provided with passages B adapted to be successively brought into communication with said ports in said shaft as the rotor revolves as shown more in detail in said Ott patent.

The rotor 5 has a series of vane-guiding and carrying slots I in which the vanes or blades 8 are slidably mounted and having outer edges engaging the inner surface of a cylinder barrel or ring 9, said blades dividing the space between the rotor and the ring into a plurality of pumping compartments IIJ with which the passages 6 communicate. The blades are preferably held against the barrel by fluid under pressure introduced against the backs of' said blades fromthe discharge line. These blades are substantially radially disposed or slightly offset from a radial line so that as the rotor revolves the barrel or ring 9 will also rotate with it. Parts of therotor including end plates (not shown) between which the ring 9 is slidably and rotatably fitted are secured together and to the body part II. of said rotor by bolts I2.

The barrel or ring 9 is mounted to turn 'freely upon a series of rollers I3 interposed between said ring and an outer race ring I4 which has diametrically disposed flat faces I5 slidably shiftable upon guide bosses I6 on the casing I1.

It is to be noted that shifting of the ring I4 will also shift the barrel 9 and will cause it to be shifted oif center relative to the rotor, and

(Cl. 10S-120) upon the ertent of eccentricity thus produced will depend the volume of pressure fluid delivered by the pump and hence' its pumping capacity. As shown in the drawing the ring I4 is provided ina thimble 28 having threaded bore V2I Ain the casing II, said rod IB having a head including a piston 22 with a spring 23 interposed between said head and the thimble 29 and normally acting on said rod I8 to move it upwardly and thus tend to shift the barrel 9. to one of its positions of greatest eccentricity. f

With this type of pump as the rotor 5 revolves clockwise, hydraulic iiuid coming in through the inlet port 3 will enter the pumping compartments I0 on the left hand side of said rotor, the

' volume of these compartments gradually enlarg- -ing and thenras these compartmentspass to the right hand side as Viewed in the drawing, they gradually contract in Volume while the fluid is forced through the passages 6 to the discharge port 4. It is to be noted that the bore 24 of the rotor body has a working t with the valve portion of the shaft 2 and that cut olf occurs when said rotor .is' passing the parts 25 of said valve shaft.

As the quantity of the hydraulic uid increases as the eccentricity of the barrel 9 increases with the rotor revolving at substantially constantl s'peed the pressure of the fluid also increases and to keep the pressure of the fluid substantially constant the pressure of this fluid is caused to act on the barrel 9 to shift it downwardly or in a direction to reduce its eccentricity. For this purpose the piston 22 is mounted to slide in a bore 26 in a barrel or cylinder 2l and is adjustably secured to theupper threaded end 28 of the rod I8 by the nut 29.. A washer 23 is preferably interposed between the piston 22 and the spring 23. The upper end of the cylinder 26' is closed oif by a cap 30 and a pipe 3I leads into the cylinder 26 above the piston so that fluid, at discharge pressure, delivered by the pump acts on the piston 22 and in opposition determines the tension of the spring 23 against which the pressure of the fluid acting on the piston has to operate. The thimble 20, it has been noted, has a threaded connection with the casing so that its position may be adjusted relative to the ring member I4 and thus serve as a stop to limit the extreme upper position of said ring when moved by the spring 23. The thimble may also be adjusted so as to stop the movement of the ring member I4 before it reaches a position for full eccentricity of the pump. The size of the piston 22 will vary with the Working pressure at which it is desired to have the pump operated.

I desire it to be understood that this invention is not to be limited to any particular form or arrangement of parts except in so far as such limitations are included in the claims.

What I claim as my invention is:

1. The combination with a pump having a rotor provided with vanes and a barrel cooperating with said vanes and rotor to form a plurality of pumping compartments, said barrel being shiftable to vary the eccentricity of the pump, a support, a cylinder on said support and connected with the discharge of said pump, av

piston Working in said cylinder in response to discharge pressure and directly connected to said barrel to shift said barrel toward a position oi.' zero eccentricity, a spring opposing the movement of said piston by the pressure fluid, means including a part of said piston to vary the tension of said spring and amember adjustably mounted on said support for limiting the eccentric position of said barrel.

2. The combination with a pump having a. rotor provided with varies and a barrel cooperating with said vanes and rotor to form a plurality of pumping compartments, said barrel being shiftable to vary the eccentrcity of the pump, a support, a cylinder on said support and connected with the discharge of said pump, a

` piston working in said cylinder in response to discharge pressure and directly connected to said barrel to shift said barrel toward a position of zero eccentricity, a member adjustably mounted on said support for limiting the eccentric position of said barrel, a spring opposing the movement of,said piston by the pressure ilu-id and mounted between said member and piston. and means including a part of said piston to vary the tension of said spring.

MALCOLM E. ERSKINE. 

